MPPT Schemes for PV System Under Normal and Partial Shading Condition: a Review

The photovoltaic system is one of the renewable energy device, which directly converts solar radiation into electricity. The I-V characteristics of PV system are nonlinear in nature and under variable Irradiance and temperature, PV system has a single operating point where the power output is maximum, known as Maximum Power Point (MPP) and the point varies on changes in atmospheric conditions and electrical load. Maximum Power Point Tracker (MPPT) is used to track MPP of solar PV system for maximum efficiency operation. The various MPPT techniques together with implementation are reported in literature. In order to choose the best technique based upon the requirements, comprehensive and comparative study should be available. The aim of this paper is to present a comprehensive review of various MPPT techniques for uniform insolation and partial shading conditions. Furthermore, the comparison of practically accepted and widely used techniques has been made based on features, such as control strategy, type of circuitry, number of control variables and cost. This review work provides a quick analysis and design help for PV systems. Article History: Received March 14, 2016; Received in revised form June 26th 2016; Accepted July 1st 2016; Available online How to Cite This Article: Sameeullah, M. and Swarup, A. (2016). MPPT Schemes for PV System under Normal and Partial Shading Condition: A Review. Int. Journal of Renewable Energy Development, 5(2), 79-94. http://dx.doi.org/10.14710/ijred.5.2.79-9

Sliding-mode controller for a photovoltaic system based on a Cuk converter

The wide range of step-up and step-down input-output voltage characteristic of the Cuk converter makes it a good candidate to interface photovoltaic arrays in both classical and distributed maximum power point tracking systems. Because its two inductor structure, Cuk converters have continuous input and output currents, which reduce the additional filtering elements usually required for interfacing dc/dc converter topologies. However, PV systems based on Cuk converters usually do not provide formal proofs of global stability under realistic conditions, which makes impossible to ensure a safe operation of the PV installation. Therefore, this paper proposes a high performance sliding-mode controller for PV systems based on Cuk converters, which regulates the PV voltage in agreement with the commands imposed by a MPPT algorithm, rejecting both load and environmental perturbations, and ensuring global stability for real operation conditions. Finally, the performance of the regulated PV system is tested using both simulations and experiments

A Review on Photo Voltaic MPPT Algorithms

A photovoltaic generator exhibits nonlinear voltage-current characteristics and its maximum power point varies with solar radiation and cell temperature. A Dc/Dc power converter is used to match the photovoltaic system to the load and to operate the PV (photo voltaic) cell array at maximum power point. Maximum Power Point Tracking (MPPT) is a process which tracks one maximum power point from PV array input, varying the ratio between the voltage and current delivered to get the most power it can. There are different techniques proposed with lot of algorithms are being used in the MPPT controller to extract the maximum power. It is very difficult for the photo voltaic designers, researchers and academic experts to select a particular MPPT technique for a particular application which requires the background knowledge and comparative features of various MPPT algorithms. This paper will be avaluable source for those who work in the photo voltaic generation, so its objective is to review the main MPPT algorithms in practice and analyzes the merits and demerits with various factors

Simulation and Analysis of Photovoltaic Stand-Alone Systems

Energy saving is biggest issue now a days, renewable energy is playing a big role in producing electricity, among them wind and solar are popular renewable energy sources. Fast tracking of global maximum power point (MPP) is a challenge, many research is going on this direction. MPP highly depends on atmospheric conditions, so our maximum power point tracking (MPPT) technique should be good enough to track MPP in dynamic atmospheric conditions. Perturb and Observer (P & O) and Incremental conductance (INC) are widely used MPPT techniques, we used INC method and simulated solar photovoltaic system in dynamic atmospheric conditions. Partial shading gives local MPPs and one global MPP, power loss occur in a shaded module because of that efficiency reduces, most of the conventional MPPT are failed to track global MPP ,to deal with this problem two kind of control strategies found in literature first one modular MPPT and second one two controller structure. MPP also highly depends on the load, as the load changes MPP changes. Extra power need to store because sometimes load requirement is lesser than the generation, in this situation a battery is needed and in night time when PV module not able to generate, power can draw from the battery. In this thesis we have discussed about the INC MPPT method for different atmospheric conditions and partial shading

Implementation of a Cascade Fault Tolerant Control and Fault Diagnosis Design for a Modular Power Supply

The main objective of this research work was to develop reliable and intelligent power sources for the future. To achieve this objective, a modular stand-alone solar energy-based direct current (DC) power supply was designed and implemented. The converter topology used is a two-stage interleaved boost converter, which is monitored in closed loop. The diagnosis method is based on analytic redundancy relations (ARRs) deduced from the bond graph (BG) model, which can be used to detect the failures of power switches, sensors, and discrete components such as the output capacitor. The proposed supervision scheme including a passive fault-tolerant cascade proportional integral sliding mode control (PI-SMC) for the two-stage boost converter connected to a solar panel is suitable for real applications. Most model-based diagnosis approaches for power converters typically deal with open circuit and short circuit faults, but the proposed method offers the advantage of detecting the failures of other vital components. Practical experiments on a newly designed and constructed prototype, along with simulations under PSIM software, confirm the efficiency of the control scheme and the successful recovery of a faulty stage by manual isolation. In future work, the automation of this reconfiguration task could be based on the successful simulation results of the diagnosis method.This research was funded by the Tunisian Ministry of Higher Education and Scientific Research

Design and Implementation of Takagi-Sugeno Fuzzy Tracking Control for a DC-DC Buck Converter

This paper presents the design and implementation of a Takagi-Sugeno (T-S) fuzzy controller for a DC-DC buck converter using Arduino board. The proposed fuzzy controller is able to pilot the states of the buck converter to track a reference model. The T-S fuzzy model is employed, firstly, to represent exactly the dynamics of the nonlinear buck converter system, and then the considered controller is designed on the basis of a concept called Virtual Desired Variables (VDVs). In this case, a two-stage design procedure is developed: i) determine the reference model according to the desired output voltage, ii) determine the fuzzy controller gains by solving a set of Linear Matrix Inequalities (LMIs). A digital implementation of the proposed T-S fuzzy controller is carried out using the ATmega328P-based Microcontroller of the Arduino Uno board. Simulations and experimental results demonstrate the validity and effectiveness of the proposed control scheme

Sliding mode control of DC/DC switching converters for photovoltaic applications

2011 - 2012The maximum power point tracking (MPPT) is one of the most important features of a system that process the energy produced by a photovoltaic generator must hold. It is necessary, in fact, to design a controller that is able to set the value of voltage or current of the generator and always ensure the working within its maximum power point. This point can considerably change its position during the day, essentially due to exogenous variations, then sunshine and temperature. The MPPT techniques presented in literature and adopted in commercially devices operate a voltage control of the photovoltaic generator and require careful design of the control parameters. It is in fact complex obtain high performance both in stationary that strongly variable conditions of sunshine without a careful choice of some parameters that affect in both conditions the performance of the algorithm for the MPPT. In this thesis has been addressed the analysis of an innovative current-based MPPT technique: the sensing of the current in the capacitor placed in parallel with the photovoltaic source is one of the innovative aspects of the proposal. The controller is based on a nonlinear control technique called ”sliding mode” of which has been developed an innovative model that allow to obtain a set of conditions and enable the designing of the controller with extreme simplicity. The model also allow to demonstrate how the performance of this MPPT control tecnique are independent not only from the characteristics and operating conditions of the photovoltaic generator, but also by the parameters of the switching converter that implements the control. This property allows a significantly simplification in the designing of the controller and improve the performance in presence of rapid changes of the irradiance. An approach to the dynamic analysis of a class of DC/DC converters controlled by a sliding mode based maximum power point tracking for photovoltaic applications has been also presented. By referring to the boost and SEPIC topologies, which are among the most interesting ones in photovoltaic applications, a simple analytical model is obtained. It accounts for the sliding mode technique that allows to perform the maximum power point tracking of the photovoltaic generator connected at the converters input terminals. Referring to the previous approach, a correction term allowing to have an increased accuracy of the model at high frequencies has been also derived. The control technique proposed has been implemented by means of low cost digital controller in order to exploit the potential offered by the hardware device and optimize the performance of the controller. An extensive experimental analysis has allowed to validate the results of the research. The laboratory measurements were conducted on prototypes of DC/DC converters, boost and SEPIC, carried out by Bitron SpA. There are a considerable experimental tests both in the time and in the frequency domain , both using source generator in laboratory than photovoltaic panels. The results and theoretical simulations have found a large validation through laboratory measurements. [edited by author]XI n.s

Design and Control of Power Converters 2019

In this book, 20 papers focused on different fields of power electronics are gathered. Approximately half of the papers are focused on different control issues and techniques, ranging from the computer-aided design of digital compensators to more specific approaches such as fuzzy or sliding control techniques. The rest of the papers are focused on the design of novel topologies. The fields in which these controls and topologies are applied are varied: MMCs, photovoltaic systems, supercapacitors and traction systems, LEDs, wireless power transfer, etc

RTDS implementation of an improved sliding mode based inverter controller for PV system

This paper proposes a novel approach for testing dynamics and control aspects of a large scale photovoltaic (PV) system in real time along with resolving design hindrances of controller parameters using Real Time Digital Simulator (RTDS). In general, the harmonic profile of a fast controller has wide distribution due to the large bandwidth of the controller. The major contribution of this paper is that the proposed control strategy gives an improved voltage harmonic profile and distribute it more around the switching frequency along with fast transient response; filter design, thus, becomes easier. The implementation of a control strategy with high bandwidth in small time steps of Real Time Digital Simulator (RTDS) is not straight forward. This paper shows a good methodology for the practitioners to implement such control scheme in RTDS. As a part of the industrial process, the controller parameters are optimized using particle swarm optimization (PSO) technique to improve the low voltage ride through (LVRT) performance under network disturbance. The response surface methodology (RSM) is well adapted to build analytical models for recovery time (Rt), maximum percentage overshoot (MPOS), settling time (Ts), and steady state error (Ess) of the voltage profile immediate after inverter under disturbance. A systematic approach of controller parameter optimization is detailed. The transient performance of the PSO based optimization method applied to the proposed sliding mode controlled PV inverter is compared with the results from genetic algorithm (GA) based optimization technique. The reported real time implementation challenges and controller optimization procedure are applicable to other control applications in the field of renewable and distributed generation systems

A novel modified sine-cosine optimized MPPT algorithm for grid integrated PV system under real operating conditions

This research work presents a modified sine-cosine optimized maximum power point tracking (MPPT) algorithm for grid integration. The developed algorithm provides the maximum power extraction from a photovoltaic (PV) panel and simplified implementation with a benefit of high convergence velocity. Moreover, the performance and ability of the modified sine-cosine optimized (MSCO) algorithm is equated with recent particle swarm optimization and artificial bee colony algorithms for comparative observation. Practical responses is analyzed under steady state, dynamic, and partial shading conditions by using dSPACE real controlling board laboratory scale hardware implementation. The MSCO-based MPPT algorithm always shows fast convergence rate, easy implementation, less computational burden and the accuracy to track the optimal PV power under varying weather conditions. The experimental results provided in this paper clearly show the validation of the proposed algorithm